The present invention relates to a monitor for display re-imaging using a non-self-light-emitting display panel such as a LCD panel, and a display re-imaging system using such a monitor for display re-imaging.
Placing monitors in a TV studio set, and shooting a scene of the television studio including the displays of the monitors by using a television camera is becoming increasingly common in recent years. Shooting a scene containing the displays of monitors by using a television camera is called as xe2x80x9cdisplay re-imagingxe2x80x9d, and a display monitor that is used for such a purpose is called as a xe2x80x9cmonitor for display re-imagingxe2x80x9d.
When such a re-imaging technique is used, for instance, in an election news broadcast program, the appeal of the program to the viewers may be increased by placing a large number of monitors in the studio to show the state of ballots of each election district on each monitor, and allow the newscaster to make comments to it in the studio.
When a commercially available ordinary monitor is placed in a television studio, and it is shot with a television camera, although the display of the monitor in the studio may look normal to human eyes, it is known that the display of the monitor as re-imaged by the television camera may look too pale and unnatural to be acceptable.
This is due to the fact that the color temperature of the monitor display is higher than the color temperature of the studio. More specifically, when the monitor display is viewed by human eyes, the image stimulus sensed by the human retina is automatically and physiologically color adjusted by the human brain so that the monitor display would not create any unnatural impression although the color temperature of the monitor display may be different from that of the studio. However, a television camera is incapable of any such automatic color adjustment unlike a human brain, and the monitor display as re-imaged by the television camera looks pale and unnatural if the color temperature of the monitor display is higher than that of the studio.
Therefore, conventionally, the monitors for display re-imaging that are used in a television studio are adjusted of their color temperature in the range of 3,000 K (Kelvin) to 3,400 K so as to match with that of the studio.
Conventionally, monitors for display re-imaging typically consisted of CRT monitors, and the color adjustment of such a CRT monitor for display re-imaging was typically accomplished by readjusting the RGB gain of the driver circuit in the stage immediately preceding the CRT. The color temperature of the CRT is lowered so as to match with the color temperature of the studio.
The CRT monitors that are currently on the market are oftentimes adjusted to have color temperatures in the range of 9,000 K to 10,000 K. In the past, the amount of color adjustment that was required to make such CRT monitors usable for display re-imaging was so great that the brightness of the monitor display had to be sacrificed.
However, the recent development in the fluorescent material and the structure of the CRT has made it possible to ensure an adequate display brightness even when the color adjustment is effected to such an extent. Therefore, the aforementioned problems can be solved by placing a simple color corrector externally of the CRT to effect the color adjustment instead of adjusting the RGB gain of the stage preceding the CRT.
It is now being contemplated to use LCDs for monitors for display re-imaging in television studios, instead of the more conventional CRT displays.
The LCD monitor has the following advantages:
1) a thin profile;
2) high image resolution;
3) less flicker when displaying computer images owing to the afterglow; and
4) low power consumption.
It also has disadvantages such as:
1) difficulty in manufacturing large displays;
2) lack of adequate brightness;
3) limited contrast;
4) narrow view angle;
5) more pronounced afterglow than CRT display;
6) shorter service life; and
7) higher cost than CRT display.
In particular, the LCD monitor has been considered as unsuitable for display re-imaging because of:
1) difficulty in manufacturing large displays;
2) lack of adequate brightness;
3) limited contrast; and
4) narrow view angle.
However, the recent advance in the LCD technology has been such that the above listed disadvantages have been significantly improved. Therefore, attempts have been made to use LCDs as monitors for display re-imaging in television studios.
The methods for adjusting the color temperature of an LCD monitor when it is used as a monitor for display re-imaging include the following:
1) controlling the RGB gain by adjusting an image signal level (RGB adjustment method); and
2) placing an optical filter in front of the LCD monitor for color adjustment (filter adjustment method).
However, either one of the adjustment methods, the RGB adjustment method or the filter adjustment method, significantly reduces the brightness of the display after the color adjustment.
In other words, as was the case with the CRT monitor, it is possible to color adjust the LCD monitor by adjusting the image signal, but the brightness of the G and B components have to be reduced for the desired color adjustment, and this inevitably reduces the overall brightness. In the case of the CRT monitor, the overall brightness can be increased after the color temperature correction to achieve a desired balance. However, because the LCD monitor has a lower brightness saturation point as compared with a CRT monitor, it is not possible to ensure an adequate brightness after the color temperature correction even when the overall brightness is increased to the maximum possible level.
The color temperature correction using an optical filter also reduces the overall brightness because the color temperature is lowered by reducing the brightness of the G and B component, and the same problem exists.
The present invention was made in view of such problems, and its primary object is to provide a monitor for display re-imaging which has a thin profile, consumes little power, and provides a bright display as compared with a CRT monitor, and a display re-imaging system using such a monitor.
Another object of the present invention is to provide a monitor for display re-imaging which has a thin profile and a high image resolution power, is free from flicker due to the high degree of afterglow when displaying a computer image, and consumes little power while ensuring a highly bright display, as well as a display re-imaging system using such a monitor.
Other objects and advantages of the present invention will become apparent to a person skilled in the art by referring to the following description.
The monitor for display re-imaging of the present invention comprises a back light having a prescribed light source; and a non-self-light-emitting display panel which selectively transmits the light of the back light according an image signal.
Additionally, the color temperature of the light source forming the back light is adjusted to match the surrounding color temperature.
The display re-imaging system of the present invention comprises a monitor for display re-imaging, and a video camera which covers the display of the monitor for display re-imaging in a part of its field of view. The video camera may include a television camera.
The monitor for display re-imaging comprises a back light having an light source which is appropriately color temperature adjusted, and a non-self-light-emitting display panel which selectively transmits the light of the back light according an image signal.
Additionally, the color temperature of the light source forming the back light is adjusted to match the color temperature of the surrounding environment. The surrounding environment includes television and video studios with various fixtures.
According to the monitor for display re-imaging and the display re-imaging system, because the color temperature adjustment is made on the back light itself, there is no problem of reducing the brightness due to the use of the RGB adjustment method or the filter adjustment method as was the case with the monitor for display re-imaging and display re-imaging system using the conventional LCD monitor. Therefore, the present invention provided a monitor for display re-imaging which has a thin profile, consumes little power, and provides a bright display as compared with a CRT monitor, and a display re-imaging system using such a monitor.
The monitor for display re-imaging and display re-imaging system of the present invention can be implemented in various manners.
The xe2x80x9cnon-self-light-emitting display panelxe2x80x9d means a display panel which displays an image by selectively transmitting light from a back light instead of emitting light by itself.
The xe2x80x9cre-imaging environmentxe2x80x9d means the environment in which the monitor in question is placed, and the re-imaging takes place. More specifically, such re-imaging environments include television studios and videos studios.
The xe2x80x9ccolor temperature of the xe2x80x9cre-imaging environmentxe2x80x9d may vary depending on the re-imaging environment, but preferably consists of a reddish color temperature if the surrounding environment consists of a television or video studio.
The xe2x80x9cnon-self-light-emitting display panelxe2x80x9d as used in the present application includes those used in LCD monitors and LCD projectors.
The xe2x80x9cback lightxe2x80x9d as used in the present application comprises cold cathode fluorescent lamps.
The xe2x80x9cnon-self-light-emitting display panelxe2x80x9d as used in the present application may include a reflective polarizing film placed in front of the back light. This increases the brightness of the monitor display.